1. Field of the Invention
The present invention relates to a loading system for a combination hole puncher and reinforcer of the type used in punching holes in sheets of material, such as paper, and for concurrently reinforcing the holes with flat, annular rings around the holes.
2. Description of the Prior Art
In offices throughout the world hole punching devices have been utilized for many years to punch holes in sheets of paper, and sometimes plastic sheets, in order to allow those sheets to be secured in files. Sheets of paper are often punched at the top with a pair of holes that allow them to be secured at the top of files using pronged fasteners. Other types of hole punchers are used to punch holes in papers and other sheets of material along the side margin to allow them to be secured in ring binders or in binders with other attachment devices.
A problem that has persisted through the years is that considerable stress is often applied to the structure of papers fastened in files in the area immediately surrounding the punched holes. The papers then tear through the short distance of material between the holes and the edges of the sheets of paper near which they are formed. When this occurs the sheets will no longer remain in the file.
One system that has been available for many years for remedying this situation is the use of flat, annular reinforcing rings that may be secured to the areas surrounding the punched holes. These reinforcing rings are typically formed of a material of greater strength than the paper or other sheet material in which the holes are punched. The reinforcing rings are coated with either a moisture-sensitive or pressure-sensitive adhesive and are applied to the sheet of paper or other material about holes formed therein once the holes have been punched.
The principal problem with this prior arrangement is that it has historically been performed manually. The task of reinforcing punched holes in the hundreds, and even thousands, of sheets of papers that are secured in files by the manual application of such reinforcing rings is often so labor intensive as to be impractical. Consequently, this system of reinforcement, while used to some extent, is not prevalent.
Various hole puncher and reinforcer devices have been created in attempts to provide alternative, more automated ways of reinforcing the structure of sheets of paper around punched holes therein. Numerous machines have been fabricated that draw segments of adhesive tape from rolls and secure them to sheets of paper or plastic contemporaneously with the perforation of those sheets. When such devices operate properly, the sheets of paper are provided with short sections of tape at the edges of the papers in which the holes are formed. Holes are punched through both the segments of tape and the underlying paper or other sheet material. One recurring problem in such devices is that some of the pressure-sensitive adhesive from the tape transfers to the tape feed and punching mechanisms. This leads to fouling and jamming of the tape advancement and punch apparatus.
An improved hole punching and reinforcing machine was developed and is described in U.S. Pat. No. 6,789,593 issued Sep. 14, 2004 and hereby incorporated by reference in its entirety. This improved system involves a hole puncher and reinforcer device that automatically applies a reinforcement about a hole that is punched in a sheet of material, but which avoids the use of adhesive tape drawn from a roll for this purpose. As a consequence, this advanced hole puncher and reinforcer avoids the problem of fouling of a feed system with adhesive transferred to the operating mechanism from a roll of tape.
A further feature of this advanced system is that it is extremely simple in construction. Unlike prior combination hole punchers and reinforcers, the advanced system does not require any elaborate, relatively complex, and expensive tape feed mechanisms. To the contrary, the only mechanism that is required for applying reinforcement about the circumference of the holes as they are punched through the sheet material is a die punch upon which the flat reinforcing rings are stacked one atop another between a broadened punching tip located at the lower extremity of the die punch shank and a pressure plate located above the stack of reinforcing rings.
Despite its advantages, however, the hole puncher and reinforcer of this advanced prior system does have certain disadvantages. Specifically, once all of the reinforcing rings have been dispensed they must be replaced with a new stack of reinforcing rings. This involves stringing the replacement rings onto the lower portion of the punch. This is a very tedious and time-consuming process.
A further refinement of this system greatly facilitated the provision of a new supply of reinforcing rings to a hole puncher and reinforcer. According to this refinement a replaceable cartridge is provided having its own punch plate and a punch rod and fully loaded with a fresh stack of reinforcing rings mounted upon the punch rod. The cartridge also contains a spring mechanism for biasing the punch rod toward a retracted position within the cartridge casing.
When all of the reinforcing rings have been used up from one cartridge, the spent cartridge, including the punch plate, punch rod, and spring thereon, is removed from the operating mechanism of the hole puncher and reinforcer. This refinement is described in U.S. patent application Ser. No. 09/937,694, filed Sep. 10, 2004, hereby incorporated by reference in its entirety. A fresh cartridge with a full load of reinforcing rings mounted on a different punch rod is then slipped into position in the frame of the hole puncher and reinforcer. The use of a preloaded cartridge avoids the necessity for reloading the punch with a new supply of reinforcing rings since the supply of replacement rings is already preloaded onto a different punch within the new cartridge. As the supply of reinforcing rings of each cartridge is used up, the entire spent cartridge is easily removed and quickly replaced.
One problem with this refinement is that each cartridge requires a disposable punch and spring mechanism, as well as a surrounding plastic case, all of which are disposable. In a consumable office supply product the added expense of a disposable punch, springs, and surrounding case of each cartridge results in an economic disadvantage in the use of this product. That is, a replacement cartridge involves not only the cost of the reinforcing rings, but also the cost of the casing, spring, and punch, all of which are discarded once all of the reinforcing rings have been used up.